In an attempt to ensure consistency in the development of Web services, major international IT vendors -- including IBM, Microsoft, BEA Systems, Oracle, Intel, Hewlett-Packard, SAP, Fujitsu and Accenture - recently formed the Web Services Interoperability Organisation (WS-I). Sun Microsystems has also been invited to join WS-I, but has not yet decided whether to do so.
This group is designed to resolve Web services interoperability problems and develop best practices for implementing sets of existing and future specifications defined by standards organisations (for example, IETF, OAGI, OASIS, OMG, UDDI, W3C). In addition to vendors, enterprise customers are also invited to join WS-I.
"WS-I will focus on low-level standards compatibilities rather than higher-level questions about interoperability between business applications," says Eion Gibson, Strategic Consultant at META Group South Africa.
"Each standard either has ambiguities or room for extension that, though sensible in the context of the individual standard, can create compatibility problems when the complete stack of standards is compiled; or when different Web services implementations are integrated," Gibson explains.
"Leading vendors realise that these problems must be identified and eliminated early if they are to convince users of the value of Web services," he adds.
The group will begin by defining "profiles," which are bundles of standards. The first of these, the Web Services Basic Profile, has already been defined to include XML Schema, SOAP, WSDL, and UDDI, leveraging standards from W3C (World Wide Web Consortium) and UDDI.org.
"WS-I plans to build test suites on top of these created profiles to develop definitions of best-practice implementation guidelines for specific types of Web services (for example, supply chain services, information broadcast services). WS-I will then run these test suites on both J2EE and .Net platforms. WS-I will also provide testing resources (ie, sniffers, analysers) so that Web services can be tested for interoperability issues and best-practice compliance," Gibson points out.
Apparently, despite the progress made to date on Internet standards - and the promise of WS-I to leverage these standards for smoothly interoperable Web services implementations -- the lack of a Web services security standard remains a significant obstacle.
"Small, initial Web services implementations can get by with existing Internet standards, such as SSL. However, security will need to be built into the core implementations of large, commercial Web services to enable them to scale," he says.
He continues: "This is already becoming a concern for pioneering companies designing the first large-scale Web services. While security is not a major concern for Web services designed to run over an intranet, behind the corporate firewall, WS-I needs to work with the standards bodies to adopt an adequate Web services security standard soon and incorporate it into its Basic Profile."
He maintains that security standards often introduce a new set of interoperability issues.
"WS-I can consider existing Internet security standards, but if these prove inadequate, it may need to wait for the acceptance of a new standard, such as Microsoft`s proposed Web services security standard -- which, so far, is backed only by Microsoft," he remarks.
According to Gibson, exactly how WS-I will operate is still nebulous in some areas.
"In part, IBM and Microsoft have purposely waited before solidifying all of the operational structures/decisions to enable other WS-I members to have input. For instance, will WS-I actively promote Web services, as its initial announcement promises? Or will it confine itself to testing, as some members have stated in response to questions? Will WS-I focus its efforts solely on generally accepted standards, such as SOAP, UDDI, and XML -- or will it try to push the establishment of new standards, such as those recently put forward by Microsoft?" he asks.
Gibson states that META Group believes that, to be successful, WS-I should focus on tests around established standards and avoid the controversies surrounding new proposals.
"Although its profiles will initially suffer from the lack of a security standard, we agree it is important for the vendors starting this effort to establish best practices for Web services implementations. Java, for instance, suffered from the lack of best-practice definitions and examples, which led to inconsistent implementations by different users. By starting early, vendors can prevent similar problems with early Web services implementations and smoothly incorporate new standards into their best practices as these standards are generally accepted," he cautions.
The WS-I announcement also did not apparently include mention of any certification process.
"The founders gave the impression that, initially, the group may rely on peer pressure to push all its members to comply with its definitions of best-practice implementations. At this point, the lack of a clear-cut certification process reflects the reality that certification processes are themselves often controversial, and the focus initially is to get all the important vendors and other participants into the organisation," Gibson reports.
He advises that user organisations should not expect WS-I`s work to impact their attempts to utilise Web services until sometime this year, or early 2003.
"Although the organisation`s founders have promised the first set of tools for its Web Services Basic Profile in June, we believe this is overly optimistic and the tools will appear during 3Q02. Vendor members will then need a few months to implement these best practices and tools in their products," he advises.
"Because WS-I is not performing compliance testing, users will need to question vendors closely on compliance and run conformance suites themselves in critical areas. Users assessing Web services should track WS-I activity, while users deploying Web services should join WS-I to build dialogue with other companies and ensure that the organisation focuses on their business needs," he concludes.
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